Long the stepchild of a Eurocentric art world, American art is finding new favor at home as a growing number of institutions showcase work from Colonial times to World War II.

Today, the Huntington in San Marino will join the Metropolitan Museum of Art and museums around the country when it unveils a renovated and expanded gallery devoted to American art.

Stern portraits of the Founding Fathers, Hudson River landscapes and scenes of the Great Depression will take a place of prominence in the 16,379-square-foot Virginia Steele Scott Galleries of American Art at the Huntington Library, Art Collections and Botanical Gardens.

This at a cultural venue best known for 18th century British "grand manner" portraits, such as Thomas Gainsborough's "The Blue Boy," Thomas Lawrence's "Pinkie" and Sir Joshua Reynolds' "Sarah Siddons as the Tragic Muse."

Experts can't pinpoint why this is happening now. They suggest at least three forces: a national coming of age, a thirst for new artistic territory and a critical mass of American material that has made its way from private homes to public museums.

In the past, says Selma Holo, director of USC's Fisher Museum and the university's International Museum Institute for Advanced Studies and Practice, "our museums featured European and English art as their most prized possessions. They were spinning a cultural lineage which was largely true but also embellished. Now we have reached a stage of maturity where we don't have to rely on Europe, but can look at art made by and for Americans."

Frances K. Pohl, professor of art history at Pomona College and author of "Framing America: A Social History of American Art," says an increasing number of television documentaries on American art and news coverage of controversial sales of American paintings have sparked public interest, along with the practice of using museum collections to teach American history in schools.

Scholars of European art once dismissed the work of American "whippersnappers" as inferior and derivative, says Jessica Todd Smith, the Huntington's curator of American art. There were no graduate courses in American art until the 1960s and literature on the subject is still relatively sparse.

But Pohl says the field is attracting more college students and researchers. "American art was so understudied that people find it easier to do interesting things on brand new topics," she says.

Morrison H. Heckscher, chairman of the Met's extensively remodeled American Wing, says that few people collected American art in the early 20th century.

"They lived with French and English antiques and European portraits of other people's families," he says. "There was no real respect for American art. But that has changed a lot in the last 30 years. There has been a great, growing interest in teaching and collecting it, and that has led to the building renovations and expansions that are cresting now."

Last week, the Met opened the American Wing, part of a $100-million makeover, with great fanfare and the blessing of First Lady Michelle Obama. The Nelson-Atkins Museum of Art in Kansas City, Mo., launched an elegant multimillion-dollar expansion of its American galleries last month.

In the last few years, the Cleveland Museum of Art and the Detroit Institute of Arts have refurbished their American art spaces. Next May, the Virginia Museum of Fine Arts in Richmond expects to complete a major expansion with added space for American art, including the bequest of a $100-million collection. Later next year in Boston, the Museum of Fine Arts plans to open an American Wing as part of a huge building project.

Private collectors are also getting into the act. Wal-Mart heiress Alice L. Walton is paying top prices for American paintings to be housed in Crystal Bridges, a privately funded museum under construction in Bentonville, Ark.

Her biggest purchase, at $35 million, is "Kindred Spirits" by Asher B. Durand, an 1849 painting acquired from the New York Public Library amid controversy over the loss of one of the city's cultural treasures.

Auctions of American art have chalked up records in recent years. Last May, "Green River of Wyoming," an 1878 landscape by Thomas Moran, had a pre-sale estimated price of $3.5 million to $5 million. It was sold to a Pennsylvania art dealer for $17.7 million, more than twice the previous auction record for a 19th century American painting.

Such sums are modest compared with top prices paid for European masterpieces and works by a few leading modern and contemporary figures, at least until the economic crisis. But they represent an astonishing rise for American art.

Other new initiatives are in the works. Boston's Museum of Fine Arts and the Los Angeles County Museum of Art are reorganizing their U.S. holdings in a broad context spanning North and South America.

At the Met, founded in 1870, the latest transformation of the American Wing has brought a display of sculpture, mosaics and stained glass in the luminous courtyard; an installation of 1,000 pieces of ceramics, glass, silver and pewter in balcony galleries; and a glass elevator that transports visitors to reconfigured period rooms.

At the 90-year-old Huntington, American art is relatively new. Founder Henry E. Huntington and his wife, Arabella, acquired a few American paintings along with their British portraits. But the institution didn't begin collecting American art until 1979, when it received a gift of 50 paintings from Virginia Steele Scott.

Today, the collection includes 9,400 paintings, sculptures, prints, drawings, furniture and other decorative arts. Fifteen galleries in the complex offer chronological and thematic displays of fine and decorative arts from the 17th through the mid-20th century.

The new showcase, a $1.6-million project designed to give the Huntington's rapidly growing American art collection more space and visibility, combines the original, 1984 American gallery with the Lois and Robert F. Erburu Gallery, a streamlined, 4-year-old structure by Los Angeles architect Frederick Fisher.

The Nelson-Atkins Museum opened in 1933, thanks to William Rockhill Nelson, a civic leader and admirer of European art who left money to buy a collection, and Mary McAfee Atkins, whose bequest paid for the building. Over the years, the museum has compiled one of the nation's strongest American collections, including paintings by Winslow Homer, Thomas Cole, John Singer Sargent and Raphaelle Peale and furniture by leading designers.

The museum's expansion provides a popular 9,000-square-foot sequence of galleries that offers historical and social narratives, curator Margaret C. Conrads says: "It's the American experience."

The current American experience is colored by economic stress.

As Heckscher observes: "It's wonderful that all these museums' initiatives, these new American displays, are getting done or have been done when money was plentiful enough to do it. Going forward, it will be much more difficult to begin any such projects, at least in the immediate future."

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